Double debit by Uber

I booked a ride with Uber and the reserved the payment of R164 upfront on my credit card. When the ride was done I was charged R180.59 for the same ride. Uber should have returned the amount of R164 to my account on the same day, which was Monday, 29 October. I have twice informed them and asked them to rectify via the Uber app but on both occasions I have not received a response from them. I have since changed my payment method to cash as I can't trust them anymore. I want them to reverse the payment of R164.